Abstract
In this paper, we study the spin Nernst effect of magnons in the nonlinear response regime. We derive the formula for the nonlinear magnon spin Nernst current by solving the Boltzmann equation and find out that it is described by an extended Berry curvature dipole of magnons. The nonlinear magnon spin Nernst effect is expected to occur in various N\'eel antiferromagnetic materials even without the Dzyaloshinskii-Moriya interaction. In particular, the nonlinear spin Nernst current in the honeycomb and diamond lattice antiferromagnets can be controlled by strain/pressure.
Highlights
The Berry phase and curvature play an essential role in modern condensed matter physics; e.g., they are responsible for polarization, orbital magnetism, and various types of Hall effects [1]
We study the magnon second-order response to the temperature gradient by solving the Boltzmann equation and show that the nonlinear magnon spin Nernst current can be described by an extended Berry curvature dipole (BCD)
We have derived the formula for the magnon spin Nernst current as a second-order response and found that it is characterized by the extended BCD
Summary
The Berry phase and curvature play an essential role in modern condensed matter physics; e.g., they are responsible for polarization, orbital magnetism, and various types of Hall effects [1]. Despite a number of studies on magnon systems, representative transport phenomena, e.g., thermal Hall effect and SNE of magnons, have been considered mostly in the magnets with the Dzyaloshinskii-Moriya interaction (DMI) or noncollinear spin configurations, which give rise to complex hopping matrix elements in the magnon Hamiltonian. This is because their manifestation as a linear response requires the integration of the magnon BC over the whole Brillouin zone to be nonzero. We investigate several other models for Néel AFMs and find the presence of the extended BCD, which results in the nonlinear magnon SNE
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
